A nurse in Palos Heights, Ill., told Gerard Nussbaum he could not stay with his father-in-law while the elderly man was being treated after a stroke. Another nurse threatened Nussbaum with arrest for scanning a medical chart to prove that she was about to administer a dangerous second round of sedatives.

The nurses who threatened him with eviction and arrest both made the same claim, Nussbaum said: that access to his father-in-law and his medical information were prohibited under the Health Insurance Portability and Accountability Act, or HIPAA, as the federal law is known.

Nussbaum, a health care and HIPAA consultant, knew better and stood his ground. Nothing in the law prevented his involvement. But the confrontation drove home the way HIPAA is misunderstood by medical professionals, and the ensuing frustration – and even peril.

Recent government studies show the frustration is widespread, an unintended consequence of the 1996 law.

HIPAA was designed to allow Americans to take their health insurance coverage with them when they changed jobs, with provisions to keep medical information confidential. But new studies have found that some health care providers apply HIPAA regulations overzealously, obstructing family members, caretakers, public health and law enforcement authorities from getting information.

Experts say many providers do not understand the law, have not trained their staff members to apply it judiciously, or are fearful of the threat of fines and jail terms – although no penalty has been levied in four years.

Some reports blame the language of the law itself, which says health care providers may share information with others unless the patient objects, but does not require them to do so. Thus, disclosures are voluntary and health care providers are left with broad discretion.

"It’s drummed into them that there are rules they have to follow without any perspective, " said Mark Rothstein, chairman of a privacy subcommittee that advises the Department of Health and Human Services. "So … they approach it in a defensive, somewhat arbitrary and unreasonable way."